EKG Review

Function of Heart• With any functioning unit you need:

Electricity and Plumbing

• ELECTRICITY: electrical current that stimulates the heart and tells it to beat or contract

• PLUMBING: When the heart contracts it provides blood and oxygenation to vessels, tissue and organs

• ***Keep in mind how electricity and plumbing affect each other!!!

Electricity

• SA AV Bundle of HIS BB PF

• SA: 60-80bpm

• AV: 40-60bpm

• BH-BB: 20-40bpm

“ACCIDENTS ON A HIGHWAY”- will be detoured around the blockage.

increased distance to travel = increased time to get to location**Electrical current needs healthy tissue to

conduct- dead tissue will not allow signal to pass through

PlumbingBeats = contractions

• Each beat requires atrial and ventricular contraction

• Heart is like a sponge. It absorbs and squeezes out blood with each contraction. If it is not “rung out fully” with each squeeze- it cannot absorb it’s full potential. (preload, afterload)

• Ventricular contraction- pushes blood into arteries to be sent to body, tissues, organs and lungs

• Tissue needs oxygen and blood to survive. Without this, it cannot function

Basic principals of EKG

• Rate? FAST, SLOW, NORMAL

• Complex? “P” in front of every “QRS”

P- atrial contractionQRS- ventricular

contraction

p

qrs

T

What is my rate:

•Each Full complex is one beat•Most strips are 6 seconds long

(# of complexes in 6 sec strip) X (10) = Heart Rate(5 complexes) X (10) = 50 beats per minute

1 2 3 4 5

ARRYTHMIAS

•Normal: 60-100 bpm

• Slow: < 60 bpm • Sinus Bradycardia, Junctional

• Fast: >100 bpm• Sinus Tachycardia, Supraventricular Tachycardia, VTach.

-CARDIA : heart beat including contraction & relaxation

Sinus Rhythm

• Sinus rhythm is normal electricity and normal plumbing.

• Electrical signal fires from ‘Sinus’ node.

Rate is either slow, fast or normal.“P wave” is present in front of every “QRS”

SLOW ARRYHMIAS

• Sinus Bradycardia• SLOW sinus rhythm

• Junctional Rhythm• “P” wave is inverted or absent

FAST ARRYTHMIAS

• Sinus Tachycardia• Fast sinus rhythm

• Supraventricular Tachycardia• Supra-superior : “above” the ventricular

• Rate is greater than 160 bpm, “QRS” is narrow.

Ventricular rhythms

• Ventricular Tachycardia• Tachycardia- firing from the ventricle• WIDE “QRS”, no “P”

• Ventricular Fibrillation• Fibrillation or “quivering” of the ventricles- no contraction/relaxation.

No organized rhythm

Atrial Arrhythmias

• Atrial Fibrillation• Underlying rhythm is sinus, with fibrillation between complexes/beats

• Atrial Flutter• Look at sawtooth pattern between waves

Asystole

•No movement of heart muscle

Just remember : “Dead meat don’t beat”

EKG GRIDSTime (secs)

VOLTAGE

SMALL blocks: 0.4 secLARGE blocks: .20 sec

5 Large blocks = 1 sec. on strip

BLOCKS

• Underlying rhythm is sinus, (must have P-QRS)

• Normal P-R interval is .12-.20 sec (one big block)

• 1st degree: prolonged P-R interval (>.20)• 2nd degree I: (WB) P-R gets longer, then drops beat• 2nd degree II: more “P’s” than “QRS” (kids w/o parents)• 3rd degree: total disassociation, no communication

Premature Complexes

•PAC- premature Atrial complex• P wave upright in front of QRS

•PJC- premature Junctional complex• P wave is inverted or absent

•PVC- premature Ventricular complex• Wide and bizarre, No “P” wave

Other things to look at….

•S-T segment

• Depression- Ischemia or injury

• Elevation- infarct or death of tissue

**STEMI- is key point in ACS algorithm

***Classified as significant if > 1 mm

Pacemaker spikes

• If Pacemaker is pacing the heart you will see a spike. To determine what is being paced, Look at location of spike

Before P: pacing ATRIA

Before QRS: Pacing VENTRICLE

Both- pacing both